Final answer:
By substituting y with 5, the expression 2y + y evaluates to 15, which is option C.
Step-by-step explanation:
To evaluate the expression using substitution for 2y + y where y = 5, the first step is to substitute the value of y into the expression:
2y + y = 2(5) + 5 = 10 + 5 = 15
So, the answer is 15, which corresponds to option C.